A clearer portrait of Nikolas Cruz, who stands accused of killing 17 people at the Marjory Stoneman Douglas High School in Florida, is emerging after multiple students have spoken out about the erratic behavior and warning signs they witnessed in recent years. One of the Cruz’s former friends told Good Morning America that she and her friends reported Cruz’s alarming behavior to school administrators several times. And other harassed students told BuzzFeed News they received numerous threatening messages from Cruz and were and verbal assaults after Cruz broke up with his girlfriend. Several students also told the publication that they had reported Cruz’s alarming behavior to school administrators.

Dana Craig, 16, said that Cruz dated her friend, who attended a different school. When the friend reported that the relationship had become abusive, Craig encouraged her to break it off. In 2016, began receiving threatening messages from the friend’s Instagram account — but Craig said Cruz had the password to the account and she believed he was the one sending the messages.

“‘I’m going to get you and I’m going to kill you because you took this person away from me. I’m going to kill your family,’ Craig remembered the messages saying,” Buzzfeed reports. Craig said she told Kevin Greenleaf, who at the time was a security specialist at Stoneman, about the messages.

Cruz’s rage also reportedly fell on Enea Sabadini, 17, who began dating Cruz’s ex after they broke up. Sabadini said that in September of 2016, he got into two fights with Cruz, the first after Cruz demanded that Sabadini stop talking to his former girlfriend. “He was also trying to stab me with pencils,” Sabadini recalled.

Nikolas Cruz appears in court with attorney Melissa McNeil (L) for a status hearing before Broward Circuit Judge Elizabeth Scherer on February 19, 2018 in Ft. Lauderdale, Florida. Cruz is facing 17 charges of premeditated murder in the mass shooting at Marjory Stoneman Douglas High School in Parkland, Florida. (Photo by Mike Stocker-Pool/Getty Images)

The second fight, which has been reported in the media, reportedly took place after Cruz threw a water bottle at Enea. Both students were suspended.

Craig and her boyfriend Matthew Rosario, 16, witnessed the second fight and told Buzzfeed news that they reported it to school administrators. “I said, ‘I know that he’s brought weapons to school. You need to take his bag. You need to check it,’” Craig recalled.

Cruz was expelled in 2017 for reasons that are not clear. But in the summer of 2017—when he had broken up with Cruz’s ex girlfriend — Sabadini began to receive menacing messages from the Instagram account @nikolasjacobcruz, which he believes belonged to Cruz.

“I am going to fucking kill you,” one of the messages reads. “I am going to watch you bleed.”

Sabadini told Buzzfeed that at the time, he wasn’t particularly concerned about Cruz because he had already been expelled from the school. “I was like, I don’t have anything to worry about,” he said.

Ariana Lopez, who was once friends with Cruz, talked about the behavior from Cruz, including many disturbing posts on social media and in-person interactions, that eventually drove them apart and caused her and her friends to go to school authorities.

“He talked about killing our parents, our friends, boyfriends and girlfriends,” Lopez said. She also talked about what sparked a fight that erupted on school grounds and was caught on camera, saying that was over a girl Cruz had briefly dated. “He would hit her, he would threaten her, he would threaten her family and her friends, for talking to other guys.”

“I knew it. We all did. Everybody who knew him knew it,” Lopez said. “Even before they announced that he was the shooter, we all knew it was Nik.” Watch her full interview below.

This is a disgrace. Where is the UK foreign office in all of this? Aras Amiri now joins another British-Iranian, Nazanin Zaghari-Ratcliffe, in notorious Evin prison on bogus charges. @foreignofficehttps://t.co/DJX0knhdot